Starter jaw advancing mechanism



June 2, 1953 TRQEGER 2,640,360

STARTER JAW ADVANCING MECHANISM Filed Feb. 28, 1952 INVENTOR. HEN/P)"TROEGER Patented June 2, 1953 rationofilielaware e Glai-msi;

presentinvention r Tat th en e starters and particularly 1:0 starter jawa'tiv aficin'g'i mechi H1 engine starters some means are necessary toadvance the starter j'aW- into engagement: with the engine aw uponemerge-amen of the starter: One method usec1?i'sa fi ie'tion n" eoritaet-witkr. the starter jaw to htfldtth jJ momentarily" against" rotatn toenablethe sdiew sham anda spline nutte' co'aet to mo've" He intking'a'g'e' ment Also, thefri'otion ri servest "diet the starter j aw initsr etraeted pesinon we theen gin'eis running? This-' method ne'enumerous dis advantages, some of which are that firietion: means: alrpresent diii ifig' the operatien of the starter; th'e' fi -ititibii Beum-es wet and doesnothavasuinei fri'c rotation to: hold the aw itsretracted por siti'ori' wh'e'ii the eng'ine is running. This is:especially a disadvantage when the: starter" is:- mounted'i with thejawse downward as is, required; in: many installations; 5150;. the?friction means do: not: periorm'v satisfactorily when low temperaturesiare encounteredt Itis: object; of my inventiorr to? provide apositive: jaw advancing mechanism incorporating positive holding; means:that: will; overcome the above diflicult-iesz- A positive holding means"pre=- vents rotation! of thestarter: jaw until: ithas moved: axiallyinto engagement." The axiai move-*- ment of the screw shaft releases theholding;

meansto-permit rotation.-

Another object of; the invention is to: p'rovlde arrimproved s'tarteriAnother. object.is toprovide =aniimproved starterfor operationatiowtemperatures;

Another object: is" to provide an! improvetia amt. novel jawadv-anoingrmeohanism 'for userin-engine starter-s.

Another object is; to providemeans for preventing the jawsfrom becoming.engaged byvibration when the engine is running, I

The above and other objectsand featuresgof the invention wi'11-. appearm'orefullyhereinafter" from. a. consideration of the followingdescription taken in connection withthe-aocompanyingzdrawings whereinoneen lfiodimentof: the invention isillust'rat'edby Way of example.

I'n'thedrawing; r

The single fig'u're isa seotionaiview' t an-engin'e' starter. embodyingone form of: the invention'.

Referring" to" the drawing, the device therein shown comprises a startenassembly inclnding, in general, a motor I; having? a. driving. shaft 2!rotatablysupported By" a bearing 3 mounted in 2 end wan! 4 of motorhousing 5. A pinion: 6}; shown; as integral with the aar-t 2 meshes withpIane't gene 7*. The planet gears T are" refit-'- any" supported by" tenbearings 3 mounted on stub" shafts 9* carried spider cage mi The'pIaEi'eiF- gear "elih' with a ring ear FF 51361 911 as' integr 3 1thgear" housing I 2 The gear housingi sharia I 35 and nuts M a'ssfli'owfio'rb'y dt-he'i" suitable means;

Integrar with ti l' snieer' cage I l is pinion gear 5 aidafified t0engage lanee gai's F6 W1 ha=1S enga e the li'n'g gear H ears" I 6 aresupported by"bearmee 1 7 mountedoristub Shafi'fS-= nut- 2 1 thr'oug'h atorque. limiting dise pack 28;!

disc: pat-c1628 comprises a plurality ofi trio-'- tion dis'csalternately" splined to" the inner face of; the barrel: and. the outerface oi thespline nut: 211m The discs of: the pack 2-8 are forcedintofriotional engagement with-t each; other by a p'Ii1-- rality of-roircumferenti'ally spaced springs: 2.9 compressed? between aflange; 341'on the barrel 25' and an adjustable nut 3ft threaded into the barrel 2&and set so thatthe disc pack 2 8 will slipat apredeterminedtorqum The"long; lead! internal threads. ofi the spline? nut 2-!- mesh with matingathreads of screw shaft 32 whiohisconne'cted to sta rter jaw Sfiaxiaisplines- 34- for' rotation therewith:

The: starter jaw 33 is securedrto a; jawretainen 35 by air-flange 3-3and snap ring 351 The out- Ward: travel of: the jaw retainer 35* islimited? by the flange 36' and the splines 34 on the screw shaft 32'; Aspring: 3'8 compressed: between the jaw retainer 3 5 and a -springretaining plate 3.9: biases the jaw 33 outward: A retaining; ring 40maintainsthe plate 39 in position;

A featureofthe present invention resides in the novel meansfor.restraining the" jaw 33 against rotation to cause axial. movementt-l'ie'recif A- restraining member 41 is provided with: a conicalsurface; Argarter spring decent-tact? against the poniealvsurf-aoe 42-to urge a; splinedi portion 4% into engagement with the splineeflk onthe starter jaw 33 that extend beyond the is secures? to the motorhousing 5' by screw shaft 32. The garter spring 43 is positioned betweenplates 45 and 46 which are secured to a bafile plate 41. The bafileplate 41 is clamped between mounting flange 48 on the housing l2 andengine mounting pad 49. Shallow grooves 50, which mate with the coils ofthe garter spring 43 on the plate 45 and conical surface 42 prevent thespring 43 from rotating. The restraining member 4| has a conical surface5| which is tapered opposite to the conical surface 4|. Outward movementof the member 4| is limited by retaining ring 52 on the screw shaft 32and retainin ring 53 on the member 4|.

An oil seal 54 is provided on the spline nut 21. Also, the spline nut 21is provided with a spline nut cap 55 to prevent oil from entering theother part of the starter.

In operation, when the starter is unenergized, the contraction of thegarter spring 43 exerts both a radial and axial pressure on therestraining member 4|. The axial pressure on the member 4| istransmitted through the screw shaft 32, spline nut cap 55, third stageplanetary spider cage 24, second stage planetary spider l9 and firststage planetary spider cage H! to the fixed wall 4 thereby clampingthese parts and tending to prevent their motion andv consequent possibledamage due to impact caused by vibration.

When the starter is in operation, the clamping pressure, due to thegarter spring reaction, is removed as will be explained later. Theplanetary spiders will be located radially by only the radial componentsof the gear tooth loads which will be free to equalize, thus avoidingthe over-stressing of the gear teeth that occurs when the planetaryspiders are rigidly supported by bearings which may not be perfectlyconcentric with the lines of action of the gear teeth.

Energizing the motor rotates the spline nut 21 through the planetarygear train and clutch pack 26. The restraining member 4| prevents thescrew shaft 32 from rotating and axial movement is imparted thereto bythe action of the helical splines connecting the screw shaft 32 to thespline nut 2'1. The screw shaft 32, upon advancing, urges the starterjaw 33 towards an extended position and also force the restrainingmember 4| further into the garter spring 43. The length of the conicalsurface 42 is so selected that when the jaw 33 has advanced a distancesufficient to insureengagement with a mating engine jaw (not shown) themember 4| will have advanced to a position where the spring 43 will becontracting on the conical surface 5|. The contraction of the spring 43will cause a thrust to the left on the member 4| causing it to move onthe screw shaft a distance equal to the space between the rings 52 and53. This space is greater than the projection of the splines on thescrew shaft and the splines on the member 4| no longer engage thesplines on the screw shaft. The starter jaw will then be free to rotate.

The amount of taper of the two oppositely conical surfaces 42 and 5|,and the strength of the spring 43 may be varied to produce differentbackward and forward thrust. By making the taper of the conical surface5| of less taper than the conical surface 42, a smaller force will berequired to return the member 4| to its rotation blocking position thanwas required to move it out of the rotation blocking position.

Although only one embodiment of the invention has been illustrated anddescribed, various changes in the form and relative arrangement of theparts may be made to suit requirements.

What is claimed is:

1. In an engine starter, an assembly comprising an axially stationaryrotatable nut, a screw shaft splined to said nut for rotation with andaxial movement relative thereto, a starter jaw member secured to saidscrew shaft for rotation and axial movement therewith, a restrainingmember movable from a position engaging said starter jaw to adisengaging position, spring means for normally biasing said restrainingmember in said engaging position, and means responsive to axial movementof said screw shaft to cause said spring means to bias said restrainingmember in said disengaging position.

2. In an engine starter, the combination of an assembly comprising anaxially stationary rotatable spline nut, a screw shaft splined in saidnut, a starter jaw member adapted for rotation with and axial movementrelative to said screw shaft, a jaw retaining member, spring meansinterposed between said jaw retaining member and said screw shaft forurging said jaw member into engagement with an engine jaw upon axialmovement of said screw shaft, a collar surrounding said jaw member andadapted for axial movement with and relative to said jaw member, splinemeans for connecting said collar to said jaw member, garter spring meansfor preventing rotation of said collar and for normally urging saidspline means into engagement, and means including a conical surface onsaid collar for urging said spline means out of engagement upon apredetermined axial movement of said screw shaft.

3. For use in an engine starter having a housing, an assembly comprisingan axially stationary rotatable spline nut, a screw shaft splined tosaid nut for rotation with and axial movement relative thereto, astarter jaw member secured to said 4. In an engine starter, the assemblycomprising an axially stationary rotatable spline nut, a screw shaftsplined to said nut for rotation with and axial movement-relativethereto, a starter jaw member splined to said screw shaft for rotationwith and axial movement thereto, said jaw member having a splinedportion normally extending beyond said screw shaft, a restraining memberhaving opposing ramp portions and spline means for engaging the splinedportion of said jaw member extending beyond said screw shaft, a springmember for normally coacting with one of said ramp portions for urgingsaid spline means into engagement with the splined portion of said jawmember to prevent rotation of said screw ing an axially stationaryrotatable splined nut, a

6 screw shaft splined to said nut for rotation with and axial movementrelative thereto, a starter References Cited In the file of 191118 p e tjaw member secured to said screw shaft for ro- UNITED STATES PATENTStation and. axial movement therewith, a restraining member having splinemeans to engage said 5 g g g st g i O 3: 1 starter jaw, a spring memberfor normally urge e c ing said restraining member into engagementFOREIGN PATENTS with said jaw, said sprin member being adapted NumberCountry Date to urge said restraining member out of engage- 468,456France 24, 19.14

ment with said jaw in response to predetermined l0 axial movement ofsaid screw shaft.

HENRY TROEGER.

